Pneumatic drop hammer



March 31, 1925.

' G. P. MACREADY ET AL PNEUMATIC DROP HAMMER 7 Filed Nov. 2, 1922 Z Sheets Sheet 1 INVENTORS Geo. Macreaafg & WM. 1 fey/770411. m 7 7 I M A TTORNEY March 31. 1925. 1,531,490

a. P. MACREADY ET AL PNEUMATIC DROP HAMMER Filed Nov. 2, 1922 2 Sheets-Sheet 2 IN VEN TORS 7 Geo. P/Vacreaay 4 0 BY Wm. 5eympur.

WM A TTORNEY Patented Mar. 31, 1925.

UNITED STATES PATENT OFFICE. I

GEORGE P. MAOREADY, OF PROVIDENCE, ANI) WILLIAM I. SEYMOUR, OF WEST BAR BINGTON, RHODE ISLAND, ASSIGNORS TO FRANKLIN MACHINE COMPANY, OF PROVIDENCE. RHODE ISLAND, A CORPORATION OF RHODE ISLAND.

rnnommrc nnor HAMMER.

Application filed November 2, 1922. Serial no. 598,472.

To all whom it-mag comer n:

Be it known that we, GEORGE P. MA- olcmor, a citizen of the United States, and resident of Providence, in the county of Providence and State of Rhode Island, and WILLIAM I. SEYMOUR, a citizen of the United States, and resident of West Barrington, in the county of Bristol and State of Rhode Island, have invented certain new and useful Improvements in Pneumatic Drop Hammers, of which the following is a specification. a

This invention relates to drop hammers and more particularly to hammers actuated by compressed air or other compressed fluid.

Some of the objects of the present invention are .to provide means for controlling the flow of compressed fluid to the operating mechanism of the drop hammer; to provide an improved valve locking device; to provide means for preventing the opening of the outlet valve until both hands of the operator are in definite positions remote from the path and impact of the weight so as to avoid injury to the operator; and to provide improved inlet and outlet valve controls of simple construction and reliable operation; and to provide an improved valve tripping mechanism and a lock therefor.

Various other objects and advantages of the invention will be in part obvious from an inspection of the accompanying drawing and in part will be more fully set forth in the following particular description of one form of mechanism embodying our invention, and the invention also consists in certain new and novel features of construction and combination of parts hereinafter set forth and claimed.

In the accompanying drawings:

Figure 1 shows a front elevation of one form of drop hammer embodying the features of the present invention; with parts broken away;

Figure 2 shows an enlarged view of a portion of the valve control mechanism of Figure 1;

Figure 3 shows a top plan view, partly in section, of the drop hammer of Figures 1 and 2;

Figure 4 is an enlarged view ofv the trip lock mechanism of Figure 1;

Figure 5 is an enlarged view of the automatic and safety levers of Figure 1; and

Figures 6 and 7 are sectional views taken on the lines 6-6 and 7-7 respectively, of Figure 3. v

The valve mechanism herein shown is claimed in applicants co-pending applica- 0 tion Serial No. 598,473 for pneumatic drop hammers, filed herewith.

weight 14 whose mass is made sufliciently 7 reat to perform the work of stamping out ewelry or other articles as may be required. The. weight is provided with a perforated protruding ear 15 for a purpose which will be subsequently set forth, and with a vertia0 cally extending connecting rod 16 which terminates in a iston 17. The, piston reciprocates in a c osely fitted cylinder 18 of suitable length, whose upper end is open to the atmosphere.

For raising the ram or hammer weight. 14 there is provided a source of compressed fluid such as a supply pipe 20 leading from a suitable air compressor of conventional design. The pipe 20 is branched to the upper and lower parts of the frame, there being rovided suitable control valves in each 0 the branches, and a ressure gauge for indicating ressure, an a drain-cock for draining moisture therefrom. A branch 21 leads to the upper portion of the frame and more particularly to a valve mechanism ositioned thereon, and shown in detail 1n Figure 3. The valve mechanism comprises a suitable housing 22 integral 16 with the lower portion of the cylinder 18 and having its interior chamber 23 communicating with that portion of the interior of the cylinder 18 below the piston 17. The housing 22 is divided by a transverse partition 24 to form an exhaust chamber 25 which may be connected to atmosphere by a suitable exhaust pipe 26.

For moving the valve ports there is pro- Vided a shaft 30 which may be journalled in a suitable boss 31 in the housing 22 and which has a bearing in the transverse partirecessed flange 34 bolted to the housing 22 so as to enclose the chamber 23. The inner end face 35 of the flange 34 is machined, and against this face there is positioned a second perforated disc or valve 36 having its contacting face ground to match with the machined surface 35. The valve 36 is securely fastened to the end of the shaft 30 in any suitable manner, as by a key. The recessed portion of the flange 34 is screwthreaded for the reception of a nipple 37 into which the air inlet 21 is in turn screwthreaded. All connections are securely sealed to prevent undesired escape of air.

For controlling the passage of air the disc 36 is provided with a' series of spaced perforations, such as 46, and the inner face 35 of the flange 34 is provided with a similar series of perforations, such as 41, adapted in one position of the disc 36 to register with the perforations therein. As shown in Figure 6 the valve port is open, since the respective perforations register, but by movement of the disc through an angle, the valve may be effectually closed. Similarly the disc 32 is provided with a series of perforations, such as 42, and the partition 24 with a series of perforations, such as 43, arranged in one position of the disc 32 to register with the perforations therein. As shown in Figure 7 the valve port is closed, since the respective series of perforations are out of register, but by movement of the disc through an angle, so that the series of perforations are in alignment, the valve may be opened. The valves 32 and 36 and the shaft 30 may be rotated into such positions of closure or opening of the valves by a reciprocating motion of a valve rod 44, loosely connected to a valve lever 45, by means of a clevis and pin connection, and this lever is mounted in fixed relation to the shaft 30 on the protruding end thereof. The valve lever 45 has an integral hub 46 which is recessed for a friction spring 47.

For supporting the valve rod 44 at its upper portion, there is provided a lugv 5O integral with one frame member 11. A bushing 51 formed of wear resisting material is mounted on the valve rod 44 suitable nuts, in such manner that the red 44 may slide through an aperture in the lug 50 with a minimum of wear. The lower end of the valve rod 44 terminates in a plunger 52 which is tightly fitted in a cylinder 53 connected by a branch pipe 54 with the. source of air 20. One side wall of the upper portion of the plunger 52 is recessed to form a cam face 55. Co-operating with the upper face of the plunger 52 is a latch 56 which is pivotally mounted upon the frame member 11 so that the plunger 52 may be maintained thereby in its lowermost position. A latch spring 57 is provided for snappin the latch, and its resiliency may be varia ly determined by a set screw 58.

For unlocking the latch, there is provided a trip lever 60 pivotally mounted on the frame member 11 so that a finger 61 integral therewith displaces the latch 56 from engagement with the plunger 52. The free end of the lever 60 forms a convenient handle, as shown. An automatic lever 62 is pivotally mounted on a suitable bracket 63 on the frame member 11 so as to be substantially parallel with the trip lever 60. A link 64 interconnects these levers at intermediate portions thereof. The automatic lever 62 is pivotally connected with the lower end of an upright automatic rod 65, whose upper end is slidabl supported in the lug 50. On an interme iate portion of the rod 65 there is mounted a collar 66, which may be adjustably positioned thereon, as by a suitable set screw.

The arm 15 comes into engagement with the collar 66 at the upper end of the travel of the weight 14, and into engagement with an adjustable stop 67 at the lower end of the travel. The stop 67 may be adjustably positioned on the valve rod 44.

For preventing the dropping of the hammer weight at undesired times, and thus preventing possibly injury to workmen, there is provided an outlet valve locking device comprising a pivoted beam 70 rotatably supported on the frame yoke 13. One end of the beam 70 is loosely connected to the upper end of a safety rod 71. The lower end of the rod 71 is loosely connected to an intermediate rtion of a safety lever 72, one end of which is pivoted to the frame member 10 opposite the one having the trip lever 60. The free end of the lever 72 is shaped to form a handle, as shown. The lever 72 and rod 71 may be locked in their upper position b a pivoted automatic safety lever 73 havlng an extension 74 upon which the lever 72 rides. The free end of the safety beam is notched to form a tooth 75 (see Figure 4), which is arranged to co-operate with a cam 76 mounted on the hub 46 to rotate therewith. The arrangement is such that when the tooth 7 5 is up the cam 76 is caught in the position shown by the full lines in Figure 4 in which the inlet valve is open and the outlet valve closed. It is impossible therefor for the weight to drop to injure a workman. The weight of the rod 71 and the leverage of the beam 70 is such that the tooth 75 tends normally to move upwardly.

For cushioning the upper impact of the weight 14, there is provided a buffer comprising a compression spring 80, held in a desired position on the rod 16 by a split collar 81.

For maintaining the weight'14 in a predetermined position when the drop hammer is not in service, there is provided a pivoted lock lever having a hooked and arranged to intercept the path of travel of the weight 14.

In operation, assuming that the operator intends to control the hammer manually. the automatic lever 7 3 is left n the position shown. The supply of compressed air or other fluid being turned on, and the valve ports being in the position shown in Figures 6 and 7, air flows through the pipe 21, apertures 40 and 41, chamber 23 into the cylinder 18, raising the piston 17. The piston is stopped when the buffer spring 80 and collar 81 are pressed against the yoke 13, and is held in its extreme upper position by the column of compressed air in the cylinder 18. The operator then adjusts the work in the proper place.

When the operator desires the weight to fall. the right hand grasps the handle of lever 60 and moves it upwardly. thus releasing the latch 56. The compressed air supplied through branch pipe 54 then exerts an upwardly directed force upon the plunger 52, tending to force the rod 44 upwards. This force encounters the resistance of the cam 76 against the tooth 75, and the rod is not moved.

With the left hand, the operator raises the handle of the lever 7 2, thus moving the rod 71 upwardly, and the tooth 75 downwardly out of engagement with the cam 76. The rod 44 is thus permitted a limited, upward movement, by a shoulder 51 on the bushing 51 striking the under side of lug 50, and the shaft 30 a limited rotary movement. The discs 32 and 36 are also rotated out of the position in which the inlet ports are open. that is the apertures 46 and 41 register, and into the position in which the outlet ports are open, that is. the respective series apertures 42 and 43 register, and the inlet ports are efiectually closed.

The ram or weight 14 is thereby relieved of support and falls by force of gravity into contact with the work. The weight 14 may be, provided with a suitable die or other tool in order to form the work into desired shape.

\Vhen it is desired to have the weight rise and fall alternately a number of times successively, the collar 66 is suitably adjusted on the rod 65 so as to control the closing of the inlet port and open the outlet port automatically. The lever 73 is rotated in a clockwise direction and displaces the safety lever 72. The operation then is as follows: Assuming the weight to be rising the ear 1? ultimately contacts with the collar 66, and thus raises the rod 65 sufficiently to raise the lever 62 and handle 60. This unlatches the trip 56 as in the case of man a1 operation. and thus permits the plunge 52 and rod 44 to move upwardly by force of the compressed air. Since the safety lever 72 is held in its uppermost position by the extension 74 of the automatic safety lever 73 which has been locked in its normal position, the finger 75 does not retard operation of the valve mechanism. The inlet valve port is accordingly closed and the outlet port opened,

permitting the weight to fall. As soon as the ear 15 contacts with the collar 67 and moves it downwardly, the outlet port is closed and inlet port opened, as described for manual operation. The weight again rises and the operation is repeated continuously until the hammer is shut down or the automatic levers restored.

Thus it will be seen that we have provided pneumatic hammer mechanism in which danger of injury to workmen is minimized when the machine is not operated, the operator having no hand leftfree from the operating mechanism to come in the danger zone. The novel positioning of the levers 72 and 60 on opposite sides of the ram or weight 14 is such that both hands are required to operate them. Additional precaution is taken by pointing the levers outwardly and by spacing them apart by approximately the -widthof a mans body. The operating mechanism and the safety devices are of sim le and rugged construction and not likely to get out of order.

While we have shown and described and have pointed out in the annexed claims certain novel features of our invention, it will means for operating said maintaining means to release said ram, manual means for rendering said last-named means active, a stop for preventing the operation of said lastnamed fluid operated means, and other manual means for disengaging said stop.

2. In pneumatic hammer mechanism, a centrally disposed slidable ram arranged to reciprocate in a vertical plane, a fluid operated piston for holding the ram in raised position, a valve for controlling the operation of said piston, a second fluid operated piston operatively interconnected to the valve for actuating the same, a control lever for controlling the second named piston positioned on one side of the path of movement of the ram, a stop for preventing the actuation of the second named piston, and a second lever positioned on a diflerent side of the path of movement of the ram for disengaging said stop.

3. In pneumatic hammer mechanism, a

centrally disposed slidable ram arranged to reclprocate in a vertical plane, a fluid operated piston for holding the ram in raised POSltl011. 3.- val've for controlling the operation of said piston, a second fluid operated piston operatively interconnected to the valve for actuating the same, avcontrol lever for controlling the second named piston positioned on one side of the path of movement of the ram, a stop for preventing the actuation of the second named piston, and a second lever positioned on .the opposite side of the path of movement of the ram for disengaging said stop.

4. In pneumatic hammer mechanism, a centrally disposed slidable ram, a piston operatively connected to the ram and movable therewith, a fiuidoperated valve for controlling the operation of said piston to permit movement of the ram, a laterally disposed control lever for said fluid operated valve. a stop for preventing the operation of the valve by said control lever, and a second laterally disposed control lever for disengaging said stop.

Signed at Providence, in the county of Providence and State of Rhode Island, this 27th day of October A. D. 1922.

GEORGE P. MACREADY. WILLIAM I. SEYMOUR. 

